The invention relates to an instrument cluster having a basic body which supports a rigid printed circuit board on its rear side and has display regions which run at different angles to one another and at least one of which is at a different level with respect to another display region.
Instrument clusters of the abovementioned type are provided in today""s motor vehicles and are therefore generally known. In order to integrate different displays in an optimum manner in the instrument cluster, the central region of the indicator of a speedometer is often covered by a display region on which, for example, a display for a vehicle navigation system is arranged. Further, secondary displays are frequently provided to the side of the speedometer, said displays running at an obtuse angle with respect to the plane of the speedometer so that they can be read in optimum fashion by the driver. Display regions running at different angles and on different levels entail a complicated arrangement and contacting of the different electrical and electronic components of the instrument cluster, and so instrument clusters of this type are substantially more expensive than instrument clusters in which all of the displays are aligned in one plane.
The invention is based on the problem of designing an instrument cluster of the type mentioned at the beginning in such a manner that in spite of different angular positions and planes of the display regions, the arrangement and contacting of the electrical and electronic components of the instrument cluster are as simple as possible.
According to the invention, this problem are solved by a flexible printed circuit board being arranged on the front side of the basic body, said printed circuit board having a connecting region which is deflected by a defined angle with respect to an edge region of the rigid printed circuit board. The defined angle may, for example, amount to approximately 180xc2x0 .
This division of the printed circuit board into a rigid printed circuit board and a flexible printed circuit board enables the required electronic and electrical components to be arranged in an optimum manner. Furthermore, the flexible printed circuit board enables even those regions of the instrument cluster which run offset in terms of height and/or angle with respect to the rigid printed circuit board or the basic body of the instrument cluster to be reached without any problems.
The connection between the rigid printed circuit board and the flexible printed circuit board can be produced with little outlay in terms of costs if, according to an advantageous development of the invention, the connecting region is connected to the rigid printed circuit board by bow-type soldering, a conductive bond or zero-force plug. The same is achieved with a rigid/flexible printed circuit board.
The assembly of the component parts of the instrument cluster is particularly simple if the basic body has a web which runs transversely to its main plane of extent and to whose free end a supporting body for a second display region is fastened, for example by means of a hinge. This design enables the supporting body to initially assume a position in which it does not obstruct the assembly of the components on the basic body. Only when the basic body has been completely fitted with the parts which it is to support is the supporting body folded onto the basic body, so that only then are other display planes, positions and/or angular positions of, for example, other elements too produced. The supporting bodies are advantageously locked in place by clips.
The instrument cluster can be produced particularly cost-effectively if, according to another development of the invention, the hinge of the supporting body is a film hinge.
It is also possible to connect the supporting body to the basic body in another manner, for example, by screwing, bonding or welding.
As the supporting body is being pivoted over the basic body it is necessarily fixed in its position aligned parallel to the basic body if there is arranged on the rear side of the supporting body at least one latching body aligned transversely to the main direction of extent of said supporting body, and the web has at least one catch for latching to the latching body as soon as the supporting body is in a defined position with respect to the basic body.
The flexible printed circuit board can be positioned on the basic body and the supporting body in a very simple manner if the flexible printed circuit board has a plurality of apertures through which a respective, for example conical body projecting from the basic body or the supporting body protrudes. This conical body is advantageously part of the basic body.
The final and permanent fixing of the flexible printed circuit board can take place without separate fixing means if there are arranged on the flexible printed circuit board indicator drives and/or light boxes which are connected rigidly to the basic body or supporting body. The indicator drives and/or light boxes can grip with latching feet through the flexible printed circuit board and can be latched in the basic body or supporting body. Further clips for holding the flexible printed circuit board may also be present as part of the basic body or supporting body. Finally, dials can be pressed onto the light boxes and the latter can be pressed onto the flexible printed circuit board and in this manner the flexible printed circuit board can be pressed onto the basic body or latching body.
Solder connections for the indicator drives, and/or other components and/or lamps in the light boxes can be dispensed with if, according to another development of the invention, the indicator drives and/or lamps and/or other components have resilient contacts which, in the fitted state, rest resiliently on strip conductors of the flexible printed circuit board.
The indicator drive for the speedometer can be arranged in a particularly simple manner and is covered toward the driver""s side if an indicator drive for a speedometer is arranged on the rigid printed circuit board, and the supporting body, in the latched state, covers a region having the indicator drive.
It is particularly expedient for the arrangement in a motor vehicle if a liquid crystal display is arranged on the supporting body because there is then the option of arranging, for example a vehicle navigation system in a central region such that it is readily visible to the driver.
A further advantage of structures of this type resides in the fact that the electrical connection system is separated spatially from electronic components, resulting inter alia in the following advantages:
Improved EMC behavior because of the optimum arrangement of the components.
Easier disentanglement of the layout.
Surface area of cost-intensive printed circuit boards reduced.
Electronics changed without affecting the mechanical structure (design etc.).